those large
chunks of
ice did to the
surrounding
ocean."
-Gregory Stone
...
and in caves that form along them, nutrients
mix and fuel the growth of tiny marine plants
called phytoplankton, the basis of the marine
food web. As they drift and melt, the bergs
leave physical and biological wakes that may
encourage the concentration of krill, fish,
jellyfish, whales, and seals.
In the months after B-15 calved, its frag
ments appeared headed for the shipping
lanes supplying McMurdo Station, where the
U.S. Antarctic Program operates year-round.
And B-15A, the largest remnant of B-15,was
positioned in a way that impeded more than
170,000 breeding pairs of emperor and Ad1lie
penguins from traveling back and forth to
their rookery at Cape Crozier.
We recruited an 18-member team of divers,
environmental scientists, and a rough-and
ready New Zealand crew, and on January 17,
2001, in the 129-foot steel-hulled Braveheart,
we set sail from Lyttelton, New Zealand. More
than 2,000 miles and two weeks later (the equiv
alent of traveling from Miami to Los Angeles
at seven miles an hour through gale-whipped
ocean) we reached the remote, ice-choked
waters of the Ross Sea.
In the end an unusually bad season of pack
ice kept us from reaching B-15B in Braveheart.
But for the five of us who dived some 90 times
into the frigid waters, the bergs that littered
the Ross Sea-many of them smaller chunks
of B-15-provided more than seven weeks of
science, exploration, and adventure.
We wanted to explore underwater places too
dangerous for open-circuit scuba gear, so we
used state-of-the-art rebreathing equipment
that allows divers to remain safely at greater
depths for longer periods by recycling exhaled
breath. The water temperature presented sep
arate problems. Seawater at 29.5°F sucks away
body heat so quickly that a naked person would die in minutes. We
wore two layers of underwear, dry suits, electric heaters, and two hoods.
Still, most of the time in the water our hands and feet throbbed with
pain. It took several months after returning home for some of us to
recover complete feeling in faces, fingers, and toes.
Although the symptoms of frostbite and neuralgia have faded, the
wonder of the expedition has not. Our observations support the
research that indicates Antarctica's monstrous bergs, some of which
can last for years, are a major factor in the biology of the Ross Sea. As
they calve, move, and melt, they play an important role in the operation
of the entire global ocean system. That system covers 70 percent of
Earth, and what we are learning in Antarctic waters will fundamentally
affect what we know about the future of our planet.
ANTARCTICA'S ICE ISLANDS